Transistors, such as field-effect transistors, are electrical building blocks used across many fields. Some transistors can act as main semiconductor switches, allowing current to pass through them when in an “on” or “closed” state or allowing them to inhibit current passing through them when in an “off” or “open” state. Placing a main semiconductor switch in an “on” or an “off” state can require the semiconductor switch being driven, such as by providing a certain voltage across the gate and source contacts of the main semiconductor switch. To operate properly, certain main semiconductor switches, such as MOSFETs, are driven using driver circuitry (e.g., a gate driver). Challenges in designing gate driver circuitry can occur, such as because of the particular semiconductor that needs to be driven or because of the environment in which the gate driver will operate.
New types of transistors, such as Silicon-Carbide (SiC) MOSFETs can provide advantages over existing Silicon (Si) MOSFETs, but also may require different driving strategies. For example, many Si MOSFETS may be driven with symmetrical voltage biases, where the positive and negative voltages are provided at the same magnitude (e.g., ±10 Volt (V)), but SiC MOSFETs may be driven with asymmetrical voltage biases, where the positive and negative voltages are provided at different magnitudes (e.g., +25 V and −10 V). Many driver circuits are incapable of providing asymmetrical voltage biases, especially in compact, high-temperature-capable packages.
Additionally, in certain environments, gate drivers are isolated. For example, galvanically isolated gate drivers may be used to drive power semiconductor switches in power processing circuits, such as power converters, power transmitters, and other such circuits. The isolation is necessary because the power switch usually does not share the same ground as the gate control circuit, such as the high-side switches in an H-bridge topology. Some isolated gate drivers include a floating power supply to provide the necessary power across its isolation barrier to drive the gate of the power switch, and an isolated signal transmission circuit to send the low-power control signal to the gate of the power switch. Such gate drivers may be bulky and complicated, especially when created for high-temperature environments (e.g., environments with a temperature above 125° C.) because of the limited choices of integrated and temperature-qualified components.
In wellbore operations, drivers for semiconductor-based circuits may be subjected to harsh environments by, for example, being used in tools that are placed within a wellbore. Drivers may need to withstand high temperatures (e.g., above 125° C.). Additionally, available space may be severely limited, necessitating drivers that are small in size or use fewer components. Finally, due to the very high costs involved in retrieving tools that have been positioned within a wellbore, drivers may need to be reliable, especially at the high temperatures described above. Other requirements may exist that further disqualify the use of existing gate driver circuits.